Population Growth of Fall Armyworm, Spodoptera frugiperda Fed on Cereal and Pulse Host Plants Cultivated in Yunnan Province, China

The fall armyworm, Spodoptera frugiperda is a major agricultural pest in China, and has migrated from its continuous breeding area to other parts of China. In our study, the biological behaviors of S. frugiperda fed on maize, wheat, barley, faba beans, and soya beans were evaluated in a growth chamber. Results indicated that maize-fed S. frugiperda larvae performed well, as evidenced by shorter larva-adult periods, adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), and generation time (T), and a higher survival rate, intrinsic (r) and finite (λ) rate of increase, and net reproductive rate (Ro), However, S. frugiperda larvae performed weakly when fed barley and faba bean plants, as indicated by lower survival rates, r, and λ, and longer pre-adult period, TPOP, and T. A heavier pupal weight of both sexes was recorded on faba beans (0.202 g) and a lighter weight on barley (0.169 g). Fecundity was higher when fed faba beans and maize, and lower when fed wheat and barley. Thus, maize was the most optimal and barley was the least optimal host plant, followed by faba beans, for S. frugiperda larvae growth and development. This study enhances our knowledge of S. frugiperda in these host plants and can help in the design of management approaches.


Introduction
S. frugiperda is one of the most common polyphagous insect pests native to America's tropical and subtropical climates [1][2][3]. It always reproduces in the subtropical and tropical areas of the Americas, but it also migrates to temperate North America during the summer [1,4]. S. frugiperda is ranked in the top 10 from the 1187 distractive and invasive arthropod species [5,6]. The pest ranked among the top 10 from the 1187 distractive an invasive arthropod species [5,6]. Due to fluctuations in dietary niches, S. frugiperda is erratic and can migrate long distances, with moths capable of traveling more than 100 km in a single night [7,8]. The dissemination and invasiveness of the pest are linked to its unique biological traits, such as lack of diapause, short generation period, high fecundity, high polyphagy, capacity for long-distance migration, and resistance to pesticides, viruses, and Bt toxins [6,7,9,10].
More than 353 species in 76 families, including many economically significant crops, such as maize, sorghum, rice, wheat, barley, oat, millet, ryegrass, soya beans, faba beans, tobacco, tomato, potato, peanut, cotton, sugarcane, alfalfa, and onion, are consumed by S. frugiperda [11][12][13]. Weeds such as bent grass, Agrostis ssp.; crabgrass, Digitaria spp.; Johnsongrass, Sorghum halepense; morning glory, Ipomoea spp.; nutsedge, Cyperus spp.; beans, barley, and wheat than when fed on maize and soya beans, and the third instar larval duration on faba beans was significantly longer than on maize, soya bean, and wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larval duration of S. frugiperda fed on faba beans and barley were significantly longer compared with larvae fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration of S. frugiperda was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p < 0.001). Thus, S. frugiperda larvae performed well when fed on maize and performed poorly on faba beans and barley. The duration in the pupal stage was significantly longer for faba beans (10.75 d), and shorter for maize (9.69 d) and barley (9.95 d) (p < 0.001). The pre-adult stage was significantly longer when S. frugiperda was fed on faba beans (34.79 d) and barley (33.05 d) and shorter when fed on maize (27.83 d) (p < 0.001). The longest adult longevity of both sexes was shown on faba beans (14.59 d) and shortest on barley (10.59 d) (p < 0.001). The longevity of female adults was longer than males when fed on maize, wheat, and barley, and shorter when fed on faba beans and soya beans. The total longevity of S. frugiperda fed on faba beans (49.38 d) was significantly longer compared to other treatments, but shorter than on maize (39.06 d) (p < 0.001). The life span of S. frugiperda fed on faba beans was longer compared to the host plants.
The survival rates of S. frugiperda at each developmental stage on the five hosts plants are indicated in Table 2. Variations in the survival rates at each larval instar, prepupal, pupal and adult stages were shown among the five host plants. The survival rate was on higher maize and lower on barley at each developmental stage. + beans, barley, and wheat than when fed on maize and soya beans, and the third instar larval duration on faba beans was significantly longer than on maize, soya bean, and wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larval duration of S. frugiperda fed on faba beans and barley were significantly longer compared with larvae fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration of S. frugiperda was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p < 0.001). Thus, S. frugiperda larvae performed well when fed on maize and performed poorly on faba beans and barley. Total longevity ( beans, barley, and wheat than when fed on maize and soya beans, and the third instar larval duration on faba beans was significantly longer than on maize, soya bean, and wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larval duration of S. frugiperda fed on faba beans and barley were significantly longer compared with larvae fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration of S. frugiperda was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p < 0.001). Thus, S. frugiperda larvae performed well when fed on maize and performed poorly on faba beans and barley. The duration in the pupal stage was significantly longer for faba beans (10.75 d), and shorter for maize (9.69 d) and barley (9.95 d) (p < 0.001). The pre-adult stage was significantly longer when S. frugiperda was fed on faba beans (34.79 d) and barley (33.05 d) and shorter when fed on maize (27.83 d) (p < 0.001). The longest adult longevity of both sexes was shown on faba beans (14.59 d) and shortest on barley (10.59 d) (p < 0.001). The longevity of female adults was longer than males when fed on maize, wheat, and barley, and shorter when fed on faba beans and soya beans. The total longevity of S. frugiperda fed on faba beans (49.38 d) was significantly longer compared to other treatments, but shorter than on maize (39.06 d) (p < 0.001). The life span of S. frugiperda fed on faba beans was longer compared to the host plants.
The survival rates of S. frugiperda at each developmental stage on the five hosts plants are indicated in Table 2. Variations in the survival rates at each larval instar, prepupal, pupal and adult stages were shown among the five host plants. The survival rate was on higher maize and lower on barley at each developmental stage.  beans, barley, and wheat than when fed on maize and soya beans, and the third instar larval duration on faba beans was significantly longer than on maize, soya bean, and wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larval duration of S. frugiperda fed on faba beans and barley were significantly longer compared with larvae fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration of S. frugiperda was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p < 0.001). Thus, S. frugiperda larvae performed well when fed on maize and performed poorly on faba beans and barley. The duration in the pupal stage was significantly longer for faba beans (10.75 d), and shorter for maize (9.69 d) and barley (9.95 d) (p < 0.001). The pre-adult stage was significantly longer when S. frugiperda was fed on faba beans (34.79 d) and barley (33.05 d) and shorter when fed on maize (27.83 d) (p < 0.001). The longest adult longevity of both sexes was shown on faba beans (14.59 d) and shortest on barley (10.59 d) (p < 0.001). The longevity of female adults was longer than males when fed on maize, wheat, and barley, and shorter when fed on faba beans and soya beans. The total longevity of S. frugiperda fed on faba beans (49.38 d) was significantly longer compared to other treatments, but shorter than on maize (39.06 d) (p < 0.001). The life span of S. frugiperda fed on faba beans was longer compared to the host plants.
The survival rates of S. frugiperda at each developmental stage on the five hosts plants are indicated in Table 2. Variations in the survival rates at each larval instar, prepupal, pupal and adult stages were shown among the five host plants. The survival rate was on higher maize and lower on barley at each developmental stage. beans, barley, and wheat than when fed on maize and soya beans, and the third instar larval duration on faba beans was significantly longer than on maize, soya bean, and wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larval duration of S. frugiperda fed on faba beans and barley were significantly longer compared with larvae fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration of S. frugiperda was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p < 0.001). Thus, S. frugiperda larvae performed well when fed on maize and performed poorly on faba beans and barley. The duration in the pupal stage was significantly longer for faba beans (10.75 d), and shorter for maize (9.69 d) and barley (9.95 d) (p < 0.001). The pre-adult stage was significantly longer when S. frugiperda was fed on faba beans (34.79 d) and barley (33.05 d) and shorter when fed on maize (27.83 d) (p < 0.001). The longest adult longevity of both sexes was shown on faba beans (14.59 d) and shortest on barley (10.59 d) (p < 0.001). The longevity of female adults was longer than males when fed on maize, wheat, and barley, and shorter when fed on faba beans and soya beans. The total longevity of S. frugiperda fed on faba beans (49.38 d) was significantly longer compared to other treatments, but shorter than on maize (39.06 d) (p < 0.001). The life span of S. frugiperda fed on faba beans was longer compared to the host plants.
The survival rates of S. frugiperda at each developmental stage on the five hosts plants are indicated in Table 2. Variations in the survival rates at each larval instar, prepupal, pupal and adult stages were shown among the five host plants. The survival rate was on higher maize and lower on barley at each developmental stage. + beans, barley, and wheat than when fed on maize and soya beans, and the third instar larval duration on faba beans was significantly longer than on maize, soya bean, and wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larval duration of S. frugiperda fed on faba beans and barley were significantly longer compared with larvae fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration of S. frugiperda was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p < 0.001). Thus, S. frugiperda larvae performed well when fed on maize and performed poorly on faba beans and barley. The duration in the pupal stage was significantly longer for faba beans (10.75 d), and shorter for maize (9.69 d) and barley (9.95 d) (p < 0.001). The pre-adult stage was significantly longer when S. frugiperda was fed on faba beans (34.79 d) and barley (33.05 d) and shorter when fed on maize (27.83 d) (p < 0.001). The longest adult longevity of both sexes was shown on faba beans (14.59 d) and shortest on barley (10.59 d) (p < 0.001). The longevity of female adults was longer than males when fed on maize, wheat, and barley, and shorter when fed on faba beans and soya beans. The total longevity of S. frugiperda fed on faba beans (49.38 d) was significantly longer compared to other treatments, but shorter than on maize (39.06 d) (p < 0.001). The life span of S. frugiperda fed on faba beans was longer compared to the host plants.
The survival rates of S. frugiperda at each developmental stage on the five hosts plants are indicated in Table 2. Variations in the survival rates at each larval instar, prepupal, pupal and adult stages were shown among the five host plants. The survival rate was on higher maize and lower on barley at each developmental stage. beans, barley, and wheat than when fed on maize and soya beans, and the third inst larval duration on faba beans was significantly longer than on maize, soya bean, an wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larval duration of frugiperda fed on faba beans and barley were significantly longer compared with larv fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration of S. frugiper was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p < 0.001). Thu S. frugiperda larvae performed well when fed on maize and performed poorly on fab beans and barley. The duration in the pupal stage was significantly longer for faba beans (10.75 d), an shorter for maize (9. The survival rates of S. frugiperda at each developmental stage on the five hosts plan are indicated in Table 2. Variations in the survival rates at each larval instar, prepupa pupal and adult stages were shown among the five host plants. The survival rate was o higher maize and lower on barley at each developmental stage.

= Male,
Plants 2023, 12, x FOR PEER REVIEW beans, barley, and wheat than when fed on maize and soya beans, and larval duration on faba beans was significantly longer than on maize, wheat (p < 0.001). The fourth, fifth, and sixth larval instars and total larva frugiperda fed on faba beans and barley were significantly longer compa fed on the other host plants (p < 0.001). Moreover, the pre-pupal duration was significantly longer on barley (2.27 d) and shorter on maize (1.40 d) (p S. frugiperda larvae performed well when fed on maize and performed beans and barley. The duration in the pupal stage was significantly longer for faba bean shorter for maize (9.69 d) and barley (9.95 d) (p < 0.001). The pre-adult sta cantly longer when S. frugiperda was fed on faba beans (34.79 d) and barle shorter when fed on maize (27.83 d) (p < 0.001). The longest adult longevi was shown on faba beans (14.59 d) and shortest on barley (10.59 d) (p < gevity of female adults was longer than males when fed on maize, wheat, shorter when fed on faba beans and soya beans. The total longevity of S. fr faba beans (49.38 d) was significantly longer compared to other treatme than on maize (39.06 d) (p < 0.001). The life span of S. frugiperda fed on longer compared to the host plants.
The survival rates of S. frugiperda at each developmental stage on the f are indicated in Table 2. Variations in the survival rates at each larval in pupal and adult stages were shown among the five host plants. The survi higher maize and lower on barley at each developmental stage. The longevity of female adults was longer than males when fed on maize, wheat, and barley, and shorter when fed on faba beans and soya beans. The total longevity of S. frugiperda fed on faba beans (49.38 d) was significantly longer compared to other treatments, but shorter than on maize (39.06 d) (p < 0.001). The life span of S. frugiperda fed on faba beans was longer compared to the host plants.
The survival rates of S. frugiperda at each developmental stage on the five hosts plants are indicated in Table 2. Variations in the survival rates at each larval instar, prepupal, pupal and adult stages were shown among the five host plants. The survival rate was on higher maize and lower on barley at each developmental stage.

Pupae Weight
Male and female pupae showed significant variations in weight when S. frugiperda fed on the five host plants (Figure 1). Male pupae fed faba beans (0.207 mg) were significantly heavier than those fed on barley (0.178 mg) and maize (0.189 mg) (p < 0.001) ( Figure 1A). Female pupae fed on faba beans (0.195 mg) were significantly heavier than those fed on barley (0.163 mg) and maize (0.182 mg) (p < 0.001) ( Figure 2B). Male pupae were relatively heavier compared to female pupae fed on the same host plant. Male pupae (0.207 mg) were significantly heavier compared to female pupae (0.176 mg) on faba beans (p < 0.001) ( Figure 1C). Therefore, the variations in pupae weight could be due to variations in nutritional content among the host plants.

Pupae Weight
Male and female pupae showed significant variations in weight when S. frugiperda fed on the five host plants (Figure 1). Male pupae fed faba beans (0.207 mg) were significantly heavier than those fed on barley (0.178 mg) and maize (0.189 mg) (p < 0.001) ( Figure  1A). Female pupae fed on faba beans (0.195 mg) were significantly heavier than those fed on barley (0.163 mg) and maize (0.182 mg) (p < 0.001) ( Figure 2B). Male pupae were relatively heavier compared to female pupae fed on the same host plant. Male pupae (0.207 mg) were significantly heavier compared to female pupae (0.176 mg) on faba beans (p < 0.001) ( Figure 1C). Therefore, the variations in pupae weight could be due to variations in nutritional content among the host plants.

Population Parameters of S. frugiperda
The host plants evaluated showed a substantial effect on whether a newly hatched neonate of S. frugiperda survived to age x and stage j (Figure 2). Due to the variations in the developmental rates among S. frugiperda individuals, clear overlaps between stages were observed among the host plants. However, a relatively higher survival rate of all developmental stages was observed in maize and wheat than in barley and soya beans. The survival rate of S. frugiperda larvae was highest when fed on maize ( Figure 2C), with 84.21% of the eggs developing into the adult stage, and the lowest was recorded on barley (65.16%) ( Figure 2E). The overall survival duration was longer in adult males than in adult  . Sxj: the probability that a newly laid egg will survive to age x and stage j.

Reproduction Parameters of S. frugiperda
The adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), oviposition period, and fecundity of S. frugiperda fed on the five host plants are indicated in

Population Parameters of S. frugiperda
The host plants evaluated showed a substantial effect on whether a newly hatched neonate of S. frugiperda survived to age x and stage j (Figure 2). Due to the variations in the developmental rates among S. frugiperda individuals, clear overlaps between stages were observed among the host plants. However, a relatively higher survival rate of all developmental stages was observed in maize and wheat than in barley and soya beans. The survival rate of S. frugiperda larvae was highest when fed on maize ( Figure 2C), with 84.21% of the eggs developing into the adult stage, and the lowest was recorded on barley (65.16%) ( Figure 2E). The overall survival duration was longer in adult males than in adult females for S. frugiperda fed on all of the host plants (Figure 2A-E). Additionally, on each host plant, female adults appeared 1-2 d earlier than males (Figure 2A-E).

Reproduction Parameters of S. frugiperda
The adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), oviposition period, and fecundity of S. frugiperda fed on the five host plants are indicated in Table 3. The APOP of S. frugiperda fed on soya beans (4.08 d) was significantly longer than on maize leaves (2.84 d) and barley (3.06 d) (p < 0.001). The TPOP of S. frugiperda fed on faba beans (37.63 d) and barley (35.26 d) were significantly longer than those fed on other host plants. The oviposition period of S. frugiperda fed on maize (6.16 d) and faba beans (6.09 d) was significantly longer than those fed on wheat (4.58 d) and barley (4.97 d) (p < 0.001). The fecundity of S. frugiperda fed on faba beans (1706.40) and maize (1705.45) was significantly higher than those fed on other host plants (p < 0.001). The female ratio of adult S. frugiperda was highest for soya beans (53.95%) and lowest for barley (30.49%).

Population Parameters of S. frugiperda
The effects of the five host plants on the population parameters of S. frugiperda are indicated in Table 4. The intrinsic rate of increase (r = 0.205 d −1 ) and finite rate of increase (λ = 1.228 d −1 ) of S. frugiperda fed on maize were significantly higher than those fed on the other host plants but were lowest on faba beans (r = 0.162 d −1 and λ = 1.176 d −1 ) and barley (r = 0.165 d −1 and λ = 1.179 d −1 ) (p < 0.01). Moreover, the net reproductive rate (R o ) of S. frugiperda fed on maize (695.64) was significantly higher than those fed on wheat (443.43) and barley (397.74) (p < 0.01). However, the mean generation time (T) of S. frugiperda fed on faba beans (39.09 d) was significantly longer than for those fed on the other host plants but was shortest on maize (31.877 d) (p < 0.001). Thus, the overall results of population parameters indicated that barley and faba beans were the least preferred host plants for S. frugiperda population growth. Table 4. Net reproductive rate (R o ), intrinsic rate of increase (r (d −1 )), finite rate of increase (λ (d −1 )), and mean generation time (T (d)) of S. frugiperda fed on five host plants.

Population Survival Rate and Fecundity of S. frugiperda
The impact of the five host plants on S. frugiperda age-specific survival rate (l x ), female age-stage specific fecundity (f x ), age-specific fecundity (m x ), and age-specific net maternity value (l x *m x ) are displayed in (Figure 3A-E). The l x curve on the five host plants indicated a decreasing trend as age increased, and the deaths of the last adults on faba bean, soya bean, maize, wheat, and barley were at 57, 52, 47, 48, and 49 d, respectively. The highest f x , m x , and l x *m x maximum peaks were attained at 31 d on maize (356.20, 166.98, and 140.61, respectively). However, the lowest f x , m x , and l x *m x maximum peaks were attained at 37 d, on barley (152.94, 88.54, and 56.71, respectively). Furthermore, the f x curve on maize and soya beans had one peak, while there were two or more peaks on the other host plants, indicating that there were significant variations in adult emergence and oviposition period among S. frugiperda individuals.

Life Expectancy of S. frugiperda
The age-stage life expectancy (exj) represents the length of time that S. frugiperda individuals of age x and stage j are expected to survive after age x ( Figure 4A-E

Life Expectancy of S. frugiperda
The age-stage life expectancy (e xj ) represents the length of time that S. frugiperda individuals of age x and stage j are expected to survive after age x ( Figure 4A-E

Discussion
S. frugiperda is a polyphagous and invasive pest that feeds on more than 353 host plants and belongs to 76 families [11,13]. It damages economically important crops such as maize, rice, sorghum, soya beans, and cotton [28,29]. Variations in host plant species affect the survival rate, growth, developmental period, and reproduction potential of phytophagous insects including S. frugiperda [20,25,30]. Every plant species has a variety of secondary metabolic and nutritional substances with unique defensive properties, including tolerance, antibiosis, antixenosis, and combinations of the three mechanisms [31,32]. We investigated the performance of S. frugiperda fed on maize, wheat, barley, faba beans, and soya beans and performed analysis using the age-stage two-sex life table approach to determine the computability of these plant species for S. frugiperda larvae.
Our research revealed that S. frugiperda populations completed their life cycle on each of the five host plants, although there were significant differences in the survival rate, developmental period, reproduction, and population growth when fed on the different host plants. According to earlier research from [20,33,34], maize is optimal for S. frugiperda survival and development because it has shorter larval, prepupal, and pupal durations, as well as a greater survival rate compared to the other host plants. Compared to the other host plants, maize and faba beans had longer oviposition periods and higher fecundities, which was consistent with earlier research on these two hosts [33]. Additionally, S. frugiperda fed on maize exhibited shorter T and increased r, λ, and R o , indicating that maize is a suitable food source for S. frugiperda survival, development, and fecundity, which is consistent with earlier research from [33][34][35].
The longer larval growth period, higher TPOP, and lower survival rate on barley and faba beans were indicators of poor larval performance compared to the other host plants examined. Due to the long-life cycles and decreasing number of generations, the lengthier larval stages suggest an inappropriate host for insect growth and development [36]. A lower rate of the initial larvae population developed into adults in barley (65.16%) and faba beans (71.03%), suggesting that those plant species may be unsuitable for S. frugiperda. Low protein content, challenges with nutrient ingestion and absorption, and physical and chemical characteristics of these plants could all play a role in the lower larval performance [5,34,37]. Moreover, S. frugiperda fed on barley and faba beans led to longer T, and decreased r and λ, indicating that those host plants are unfavorable for S. frugiperda survival and development, which is consistent with findings from [33,38]. The prolonged TPOP of S. frugiperda on faba beans and barley contributed to the lower r and λ values. This is most likely caused by the presence of some harmful chemicals and a lack of essential nutrients in the plants [39]. The lowest R o and fecundity were recorded on barley and wheat, indicating that the nutrients from barley and wheat were less supportive for S. frugiperda reproduction. However, prior research has demonstrated that S. frugiperda has a higher R o and fecundity when fed on wheat than on pulse crops [20,33]. The highest pupa weight, longest duration of the larval stage, and highest adult longevity was recorded when S. frugiperda was fed on faba beans. This contradicted earlier findings that showed S. frugiperda fed on faba beans resulted in lower pupal weight and shorter adult longevity than maize and wheat [6,20,33]. Larvae raised on greater carbohydrate-content plants develop a heavier pupal weight, and adults with prolonged larval and pupal development are more resistant to desiccation and hunger for longer periods compared to larvae raised on protein-rich plants [40,41]. The increased duration of the larval developmental period when reared on quality host plants can be a compensation mechanism to gain additional pupal weight and complete its life cycle [34]. The pupal weight and fecundity of S. frugiperda fed on faba beans were higher compared to the other host plants, indicating a positive relationship between the two parameters. Male pupa weights of S. frugiperda fed on the five host plants were greater than female pupa weights. Intriguingly, our findings indicated that female S. frugiperda pupae emerged 1-2 d earlier than male pupae, which is in line with other observations [6,33,42]. We hypothesized that this could be to female S. frugiperda migrating early in search of food and oviposition sites.
The s xj curves showed an overlapping tendency due to variations in developmental rates among S. frugiperda individuals, which is comparable to prior reports from [6,9,20,22,33,43]. S. frugiperda had a higher survival rate on maize (84.21%) than it did on barley (65.16%). S. frugiperda individuals of the same age in different stages showed variability in e xj and v xj values, which is consistent with observations from [6,20]. The e xj values showed a declining tendency on all of the host plants; the longest average e xj values of S. frugiperda individuals were on faba beans (40.69 d) and the shortest value was on barley (33.71 d). Maize (968.69) and wheat (573.65) had slightly earlier v xj peaks at 30 d, whereas the v xj peaks on faba beans (997.89) had slightly later v xj peaks at 35 d. The e xj is examined using the s xj , assuming that the population receives a constant age-stage distribution. Therefore, it could be useful for predicting the population's survival in that situation. To create effective control strategies, it is critical to accurately predict future S. frugiperda populations.

Insects and Host Plants
Corn strain S. frugiperda that had been raised for more than ten generations in a Key Laboratory of Green Prevention and Control of Agricultural Transboundary Pests of Agriculture Environment and Resources Institute, Yunnan Academy of Agricultural Sciences (YAAS), in Yunnan Province, China, was used for the experiment. Insects were maintained at 25 ± 1 • C, 70 ± 5% relative humidity (RH), and 16 h L:8 h D photoperiod. Leaves of five plants species: maize (Zea mays L.), wheat (Triticum aestivum L.), barley (Hordeum vulgare), faba beans (Visia faba), and soya beans (Glycine max) were used in the population growth and life table study of S. frugiperda. Seeds of all plant species were collected from YAAS. The collected seeds of individual plant species were planted separately in plastic pots (10 × 15 cm 2 ) filled with a 3:1:1 combination of commercial peat. All plants were maintained in the same climate-controlled room. We used 25 d old wheat and barley, 15 d old maize, 20 d old faba beans, and soya beans seedlings, which were selected based on the growth cycle and planting conditions in the field of these plant species [33].

Population Growth and Life Table of S. frugiperda
The population growth and life table study of S. frugiperda fed on five host plants was performed using previously outlined methods [20,33,42]. Approximately 180 eggs of S. frugiperda laid within 6 h were removed from the growth chamber and placed in a Petri dish (12.0 cm in diameter and 2.0 cm in height) until hatching began. The filter paper was placed at the bottom of the petri dish, and a small drop of water was dropped to maintain the required level of humidity (about 65-75% RH). Every 6 h, the eggs were checked, and the number of hatching larvae was recorded. Single first instar larvae were transferred from the petri dish to a plastic cup (3 × 4 × 3.5 cm 3 ) with tiny holes using a soft camel hairbrush. To prevent microbial contamination, the leaves that were given to the larvae were replaced every 24 h. In total, 76, 97, 89, 107, and 105 neonates were used for maize, wheat, barley, faba beans, and soya beans, respectively. Survival and development of the larvae were monitored and recorded daily. Each freshly pupated larva was collected once every 24 h and weighed using an electronic balance. After being sexed, each pupa was placed in a cotton-lined plastic cup. Daily inspections of the pupae were made until adult emergence. The newly emerged adults from the same host plant were paired and put into separate transparent plastic cylindrical boxes (8.5 × 6 cm 2 ). For adult nutrition, a cotton ball dipped in a 10% honey-water solution was used. Folded buffer paper was inserted as an oviposition substrate. The cotton ball and buffer paper were changed every day until the adults' demise. If the male died, a new male from the same mass-reared colony was inserted until the female died. Newly deposited eggs were collected and counted daily until the adults' demise. All tests were performed in a growth chamber at 25 ± 1 • C, 70 ± 5% RH, and 16 h light: 8 h darkness.

Life Table Data Analysis
The life table data of S. frugiperda were estimated using the TWO-SEX-MSChart program [44] according to the age-stage, two-sex life table technique [45,46]. The age-specific survival rate (s xj ) (x = age, j = stage), which is the likelihood that a newly laid egg survives to age x and stage j, and fecundity f xj , estimates the number of eggs deposited by an adult female at x. Age-specific fecundity (m x ), age-specific maternity (l x m x ), intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R o ), and mean generation time (T) were analyzed. Age-specific survival rate (l x ): the probability that a newly deposited egg will survive to age x was estimated as: where m is the number of stages. Age-specific fecundity (m x ): the number of eggs per individual at age x was estimated as: The intrinsic rate of increase (r) was estimated using the Euler-Lotka equation with age indexed from 0 as follows [47].
The net reproductive rate (R o ), which is defined as the total number of offspring that an individual female adult can have over their lifetime, was estimated as: The finite rate (

Life Table Data Analysis
The life table data of S. frugiperda were estimated using the TWO-SEX-MSChart program [44] according to the age-stage, two-sex life table technique [45,46]. The age-specific survival rate (sxj) (x = age, j = stage), which is the likelihood that a newly laid egg survives to age x and stage j, and fecundity fxj, estimates the number of eggs deposited by an adult female at x. Age-specific fecundity (mx), age-specific maternity (lxmx), intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (Ro), and mean generation time (T) were analyzed. Age-specific survival rate (lx): the probability that a newly deposited egg will survive to age x was estimated as: where m is the number of stages. Age-specific fecundity (mx): the number of eggs per individual at age x was estimated as: The intrinsic rate of increase (r) was estimated using the Euler-Lotka equation with age indexed from 0 as follows [47].
The net reproductive rate (Ro), which is defined as the total number of offspring that an individual female adult can have over their lifetime, was estimated as: The finite rate (ƛ) is estimated as follows: The mean generation time (T) shows how long it takes for a population to grow to RO-fold of its current size as the time approaches infinity and the population settles to a stable age-stage distribution. Mean generation time was estimated as follows: Age-stage specific life expectancy (exy) (i.e., the time that an individual of age x and stage y is expected to live) was calculated using the method described by [48]: ) is estimated as follows: Plants 2023, 12, x FOR PEER REVIEW

Life Table Data Analysis
The life table data of S. frugiperda were estimated using the TWO-SEX-M gram [44] according to the age-stage, two-sex life table technique [45,46]. The survival rate (sxj) (x = age, j = stage), which is the likelihood that a newly laid e to age x and stage j, and fecundity fxj, estimates the number of eggs deposited female at x. Age-specific fecundity (mx), age-specific maternity (lxmx), intrins crease (r), finite rate of increase (λ), net reproductive rate (Ro), and mean gen (T) were analyzed. Age-specific survival rate (lx): the probability that a new egg will survive to age x was estimated as:

=
where m is the number of stages.
Age-specific fecundity (mx): the number of eggs per individual at age x w as:

= ∕
The intrinsic rate of increase (r) was estimated using the Euler-Lotka eq age indexed from 0 as follows [47].
The net reproductive rate (Ro), which is defined as the total number of o an individual female adult can have over their lifetime, was estimated as:

=
The finite rate (ƛ) is estimated as follows: The mean generation time (T) shows how long it takes for a population RO-fold of its current size as the time approaches infinity and the population stable age-stage distribution. Mean generation time was estimated as follows = ln Age-stage specific life expectancy (exy) (i.e., the time that an individual stage y is expected to live) was calculated using the method described by [48 The mean generation time (T) shows how long it takes for a population to grow to R o -fold of its current size as the time approaches infinity and the population settles to a stable age-stage distribution. Mean generation time was estimated as follows: Age-stage specific life expectancy (e xy ) (i.e., the time that an individual of age x and stage y is expected to live) was calculated using the method described by [48]: where s ij is the likelihood that an individual of age x and stage y will survive to age i and stage j.
Age-stage-specific reproductive value (V xj ) is the contribution of individuals of age x and stage y to the future population and was estimated as follows: The means and standard errors were analyzed via the bootstrap method with 100,000 repeats [49]; and the variations among treatments were analyzed using a paired bootstrap test [6,50]. All graphics were analyzed using Graphic Pad Prism 8.0 tool.

Conclusions
The life cycle of S. frugiperda populations was completed on all five host plants, but variations were observed in survival rate, development, reproduction, and population growth among the host plants. The shortest larval and pupal durations, APOP and TPOP, and highest survival rate were recorded for S. frugiperda fed on maize. The longest oviposition period and the highest fecundity were recorded on maize and faba beans. In addition to the prolonged oviposition period, S. frugiperda had the highest pupa weight and longest adult longevity when fed on faba beans, factors that could contribute to higher fecundity. The lowest survival rate, longest larval period, TPOP and T, and decreased r and λ were shown for S. frugiperda fed on barley and faba beans, indicating that those host plants were unsuitable for S. frugiperda survival and development. The lowest R o and fecundity were shown on barley and wheat compared with the other host plants, indicating that those host plants were less supportive for S. frugiperda reproduction. The s xj curves showed an overlapping trend due to differences in the developmental rates among S. frugiperda individuals. The e xj values showed a decreasing trend on the five host plants, while the longest average e xj values were on faba beans (40.69 d) and the shortest was on barley (33.71 d). The overall result indicated that S. frugiperda had a high preference for maize and a low preference for barley and faba beans, which could help forecast the population's survival. In conclusion, it is important to precisely forecast the development of S. frugiperda populations to establish effective control practices.